Crystal structures and Hirshfeld surfaces of differently substituted ( E )- N '-benzyl-idene- N -methyl-2-(thio-phen-2-yl)acetohydrazides.

The syntheses and crystal structures of ( E )- N '-(3-cyano-benzyl-idene)- N -methyl-2-(thio-phen-2-yl)acetohydrazide, C ₁₅ H ₁₃ N ₃ OS, (I), and ( E )- N '-(4-meth-oxy-benzyl-idene)- N -methyl-2-(thio-phen-2-yl)acetohydrazide, C ₁₅ H ₁₆ N ₂ O ₂ S, (II), with different substituents in the meta and para position of the benzene ring are described. Compounds (I) and (II) both crystallize with two mol-ecules in the asymmetric unit, with generally similar conformations [r.m.s. overlay fits for (I) and (II) of 0.334 and 0.280 Å, respectively] that approximate to L-shapes. The thio-phene rings in (I) are well ordered, whereas those in (II) exhibit 'flip' rotational disorder [occupancies 0.662 (2) and 0.338 (2) for mol-ecule 1, and 0.549 (3) and 0.451 (3) for mol-ecule 2]. The packing for (I) features short C-H⋯O inter-actions arising from the C-H grouping adjacent to the cyanide group and C-H⋯N _c (c = cyanide) links arising from the methine groups to generate [110] double chains. Weak C-H⋯π inter-actions inter-link the chains into a three-dimensional network. The packing for (II) features numerous C-H⋯O and C-H⋯π inter-actions arising from different donor groups to generate a three-dimensional network. Hirshfeld fingerprint plots indicate significant differences in the percentage contact surfaces for (I) and (II).